There are a number of great Instructables on LED grids out there.  This is a low cost version - not quite as polished, but easy to make.

This project uses a couple of sheets of foam core, a fluorescent fixture cover from the local home store, a cut up strip of WS2812b LEDs, and an Arduino.  All fairly inexpensive if you know where to get them (info below).

  • LEDs - this project uses 25 LEDs, and there are a few choices here.  For this one, a strip of WS2812b LEDs was used.  There were 30 per meter in the strip I ordered, which makes soldering easier since they are farther apart.  The 60/meter strips would also work.  The 144/meter would not work since they only have one set of solder pads between each LED to allow them to be so close, and for this project, we are soldering wires between them all and need soldering pads on both sides.  You could also use the WS2801 based strands, and those are typically pre-wired, making the project even easier.  The other Instructables cover those pretty well, so this one will not go into more detail on those.  Use non-waterproof or silicone jacketed (the jacket can be slid or cut off) strips.  Avoid the epoxy waterproofed ones since you will need to clean that off of each end of each LED - doable, but unnecessary work if you order the other kind.
  • Foam Core - 2 sheets, 20"x30", like these, though that link is 5x more than you need.
  • Plastic cover - this is from the local home store and is used to cover fluorescent bulb fixtures.  It's called an acrylic lighting panel, and the style is cracked ice.  There are other possibilities here - the main thing is there is enough frosting to diffuse the LED light.  Since the lighting panels are about 24"x 48", you can make two of these projects with one of them.
  • Wire - each LED will have wires to connect to the next one - three wires between each.  Hobby servo wire is nice to use since it's already three wires and color coded nicely.
  • An Arduino Uno will do.  Clone Arduinos are are available for about $10 each - a key for the low cost goal of this project.  There are also smaller versions of Arduinos that would also work well for this project in that same price range.  Older Arduinos will work fine too.
  • Recommended - a power jack to supply 5 volts to the system.  You can use the Arduino power and regulator if most of the LEDs are not on at the same time, but if they will all be on, the external 5 volts supply will avoid overheating the Arduino regulator.  This jac will match your power supply - for me, it was a 2.1mm ID, 5.5 mm OD panel mount jack.

Hossman33321 days ago
nodoubtman9 months ago

no code :(

CarlS (author)  nodoubtman9 months ago

The video is mostly just showing the strandtest example from the Neopixel library from Adafruit. You can get that here: https://github.com/adafruit/Adafruit_NeoPixel

There are other libraries like FastLED that are good too: https://github.com/FastLED/FastLED - many samples there.

I may do another Instructable on making it controllable over the web - similar to my LED Tower one: http://www.instructables.com/id/Web-Controlled-Wifi-LED-Tower/

Hope that helps!

could you make a video of you making the LED Grid

CarlS (author)  MootyDuck991 year ago
Good idea! I am not sure when I will make another one, but if I do, I could capture a build video.
I'm curious, did you cut the LEDs from the strip because the spacing was wrong for the project? Could they be used as supplied and the grid size adjusted?
CarlS (author)  monkeyracing1 year ago
Yes - they were cut and wired so there would be one LED per grid element. The WS2801 strands are pre-wired - slightly different, but very popular for this kind of project. If you wanted to run a full strip of the WS2811/WS2812 LEDs across each row, say, you could probably make it work. You would still want to wire each row to the next. You could either use a much finer grid to get one LED per cell, or have a few LEDs per cell. These LEDS are very bright, so that would be an intense display!
Thanks. I'd more than likely adjust the size of the project to the spacing. I love soldering, but my love has limits!
MoonDocker1 year ago
Awesome idea! Finally a project that does not use a 3D printer. I like the idea of using the foam board. I often thought of that. Simple and easy. I would cover the wires with some white tape.
CarlS (author)  MoonDocker1 year ago
Thanks. I think covering the wires is not needed - I had a few loops sticking up that you can see in the pictures, but I hot-melt glued them down, and they do not show up now. Hiding the Arduino is trickier - I tried covering it with paper, but that makes a shadow - it would either need to be below the LED, outside the box, or one of tiny compatible boards. It is not a huge obstruction, though.
hey we should combine this with my software http://www.instructables.com/id/arduino-powered-light-show/
CarlS (author)  kyle brinkerhoff1 year ago
Cool project! I have seen a number of ones where people put a lot of lights outside their house, and then manually sequence a whole show to a specific song. This is one that I saw recently: https://plus.google.com/+GregScull/posts/4aDiZ6AdfGQ?cfem=1
dharris351 year ago
Could you make something like this for a beat machine?
CarlS (author)  dharris351 year ago
You'd need to add touch sensors for each grid element - I have definitely seen other projects like this - don't have a URL handy, but if I come across any, I will post them.
What a great effect for such simple materials. :D
CarlS (author)  jessyratfink1 year ago
Thanks! Working on a holiday program now...